1. Field of the Invention
The present invention relates to an ultrasonic transducer employed for an ultrasonic diagnostic apparatus and the like.
2. Description of the Related Art
In the medical field, various types of ultrasonic diagnostic apparatuses have been proposed in conventional art wherein information regarding living body tissue is obtained by transmitting an ultrasonic wave toward the living body tissue from an ultrasonic transducer, and also receiving a reflected wave reflected by the living body tissue with the same ultrasonic transducer as the ultrasonic transducer which transmitted the ultrasonic wave, or another ultrasonic transducer provided in another member to perform signal processing for making an image.
Examples of ultrasonic transducers employed for such an ultrasonic diagnostic apparatus include an ultrasonic transducer employing the electronic scanning method wherein a plurality of piezoelectric devices are arrayed regularly, and driven sequentially. Examples of such an ultrasonic transducer include a radial-array type wherein a plurality of piezoelectric devices are arrayed in a cylindrical shape, a convex-array type arrayed in a generally partially cylindrical shape, and a linear-array type arrayed in a flat plate shape.
Of these, the radial-array ultrasonic transducer is applied to the ultrasonic probe disclosed in Japanese Unexamined Patent Application Publication No. 2-271839, for example. With this ultrasonic transducer, a transducer unit is formed by sequentially bonding piezoelectric device plates and acoustic-matching layers of which materials are lead zirconate titanate, or the like to a supporting member made up of a thin plate having flexibility with damper effects. Subsequently, a transducer array having a plurality of ultrasonic transducers are configured by forming grooves in a predetermined pitch orthogonal to one side in the longitudinal direction using cutting means while excluding lower supporting members, and the backsides of the supporting members making up this transducer array are bonded and formed around a damper member (backing member described in the specification of the present application) also serving as a circular fixing member.
Also, with Japanese Patent No. 2502685, the method for manufacturing an ultrasonic probe has been disclosed wherein a first acoustic matching layer, and a backside load member made up of a deformable member or the like, on both sides of a piezoelectric device is provided, grooves reaching part of the backside load member from the first acoustic matching layer side are formed in a predetermined interval using cutting means, and the backside load member is bonded and fixed on the outer side of a curved member formed with a desired curvature.
Also, an example of the above array ultrasonic transducer has been disclosed in Japanese Unexamined Patent Application Publication No. 10-308997. This ultrasonic transducer is formed by forming a recessed portion made up of a groove or a notch on at least any one of the first side and the second side of a piezoelectric member having electrodes, and engaging a conductive member with this recessed portion, and also electrically connecting this conductive member to the electrode near the recessed portion.
Also, with Japanese Patent No. 2729442, the ultrasonic probe has been disclosed wherein the ultrasonic probe comprises an ultrasonic transducer, a ground electrode provided on the front surface side of this ultrasonic transducer, a positive electrode provided on the back surface side of the ultrasonic transducer, an acoustic matching layer bonded on the ground electrode surface side of the ultrasonic transducer, and a conductive member for forming a superimposed structure by superimposing the acoustic matching layer and a backside load member provided on the positive electrode side of the ultrasonic transducer, also exposing the ground electrode by cutting and removing part of the side edge portion of one-side of this superimposed structure from the acoustic matching layer on the front surface side to the backside load member on the back surface side, and electrically connecting the cut surface of the backside load member and the edge surface of the ground electrode by firmly fixing the conductive member, which is connected to the positive electrode.
Also, the electronic scanning ultrasonic probe according to Japanese Unexamined Patent Application Publication No. 2-271843 has been disclosed wherein a damper member is flowed into a cylinder made up of a transducer unit to make up a radial scanning ultrasonic probe.